The Effects of a High Protein Diet on Microbiota, Gastrointestinal Function and Wellness in Older Women

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The purpose of the proposed study is to determine the effects of consuming a high protein diet on fecal microbial communities, gastrointestinal function and symptoms, and general wellness in older adults.

Older women will be randomized to a 18-week crossover study design. During each treatment period participants will be provided with a weight maintenance diet providing approximately 2 g/kg/day of protein.

Following a two-week baseline and in random order will have the following diets assigned:

The participants will be provided with a weight maintenance, high protein diet for two weeks, then for two-weeks will resume their normal diet;

The participants will come back into clinic and for the next two weeks to receive a high protein diet with a multi-strain probiotic for two weeks, then for two-weeks will resume their normal diet;

The participants will come back into clinic and for the next two weeks will receive a high protein diet with a prebiotic, then for two-weeks will resume their normal diet;

The participants will come back into clinic and for the next two weeks will receive a high protein diet with the synbiotic combination. then for two-weeks will resume their normal diet

Participants and researchers will be blinded for each treatment period (participants will receive a probiotic or placebo capsule, and a prebiotic or placebo sachet).

The following will be performed during the clinic visits: Questionnaires will assess quality of life (QoL), wellness, gastrointestinal symptoms, bowel movement frequency, and compliance. Hand-grip strength will be measured. Blood and urine samples will be collected at baseline and at weeks 2, 6,10 and 14. Stool samples will be collected at baseline and at weeks 2, 4, 6, 8,10, 12, 14 and 16.

The Effects of a High Protein Diet on Microbiota, Gastrointestinal Function, Wellness and the Potential Mitigating Effects of a Multi-strain Probiotic, Prebiotic, and Synbiotic: a Randomized, Double-blinded Crossover Study in Older Women.

Participants will be randomly assigned to receive all of the following in random order: a probiotic capsule and fiber sachet daily for 2-weeks, a probiotic capsule and placebo sachet for 2-weeks, a fiber sachet and placebo capsule for 2-weeks, and placebo capsule and placebo sachet for 2-weeks. Each treatment period is separated by a 2-week washout. During each treatment period, in addition to consuming a probiotic capsule or placebo and/or a fiber sachet or placebo sachet participants will be on a controlled higher protein diet.

Dietary Supplement: Probiotic capsule and Placebo sachet

A probiotic capsule and placebo sachet will be consumed daily for 2-weeks. The probiotic capsule contains a mixture of Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Lactobacillus acidophilus and Lactobacillus plantarum. The placebo sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the probiotic capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Fiber Sachet

A placebo capsule and fiber sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of chicory root fiber.

During the treatment period, in addition to consuming the placebo capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Placebo sachet

A placebo capsule and placebo sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the placebo capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Experimental: Probiotic capsule and Placebo sachet

Participants will be randomly assigned to receive all of the following in random order: a probiotic capsule and fiber sachet daily for 2-weeks, a probiotic capsule and placebo sachet for 2-weeks, a fiber sachet and placebo capsule for 2-weeks, and placebo capsule and placebo sachet for 2-weeks. Each treatment period is separated by a 2-week washout. During each treatment period, in addition to consuming a probiotic capsule or placebo and/or a fiber sachet or placebo sachet participants will be on a controlled higher protein diet.

During the treatment period, in addition to consuming the probiotic capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Fiber Sachet

A placebo capsule and fiber sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of chicory root fiber.

During the treatment period, in addition to consuming the placebo capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Placebo sachet

A placebo capsule and placebo sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the placebo capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Experimental: Placebo capsule and Fiber sachet

Participants will be randomly assigned to receive all of the following in random order: a probiotic capsule and fiber sachet daily for 2-weeks, a probiotic capsule and placebo sachet for 2-weeks, a fiber sachet and placebo capsule for 2-weeks, and placebo capsule and placebo sachet for 2-weeks. Each treatment period is separated by a 2-week washout. During each treatment period, in addition to consuming a probiotic capsule or placebo and/or a fiber sachet or placebo sachet participants will be on a controlled higher protein diet.

During the treatment period, in addition to consuming the probiotic capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Probiotic capsule and Placebo sachet

A probiotic capsule and placebo sachet will be consumed daily for 2-weeks. The probiotic capsule contains a mixture of Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Lactobacillus acidophilus and Lactobacillus plantarum. The placebo sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the probiotic capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Placebo sachet

A placebo capsule and placebo sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the placebo capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Placebo Comparator: Placebo capsule and Placebo sachet

Participants will be randomly assigned to receive all of the following in random order: a probiotic capsule and fiber sachet daily for 2-weeks, a probiotic capsule and placebo sachet for 2-weeks, a fiber sachet and placebo capsule for 2-weeks, and placebo capsule and placebo sachet for 2-weeks. Each treatment period is separated by a 2-week washout. During each treatment period, in addition to consuming a probiotic capsule or placebo and/or a fiber sachet or placebo sachet participants will be on a controlled higher protein diet.

During the treatment period, in addition to consuming the probiotic capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Probiotic capsule and Placebo sachet

A probiotic capsule and placebo sachet will be consumed daily for 2-weeks. The probiotic capsule contains a mixture of Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Lactobacillus acidophilus and Lactobacillus plantarum. The placebo sachet consists of 5 g of maltodextrin.

During the treatment period, in addition to consuming the probiotic capsule and placebo sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Dietary Supplement: Placebo capsule and Fiber Sachet

A placebo capsule and fiber sachet will be consumed daily for 2-weeks. The placebo capsule will contain potato starch, magnesium stearate and ascorbic acid. The fiber sachet consists of 5 g of chicory root fiber.

During the treatment period, in addition to consuming the placebo capsule and fiber sachet participants will consume a controlled diet consisting of foods that provide an average of approximately 2 g/kg/day of protein.

Measured by gastrointestinal symptoms (gas, bloating, diarrhea, etc.) assessed using a daily questionnaire. The daily questionnaire will include questions regarding symptoms and the Bristol Stool Scale (stool form and transit).

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have had or are currently being treated for any known illnesses or conditions that may impact perceived health such as HIV/AIDS, immune modulating diseases (autoimmune, hepatitis, cancer, etc.), diabetes or chronic kidney disease